Machine tool



May 24, 1938. F. A. PARsoNs ET AL MACHINE TOOL Filed Nov. 4, 1956 8Sheets-Sheet l 7 I & ggx'zxroxs B 41/5 /71 5 222 ATTO "E May 24, 1938.

F. A. PARSONS ET AL MACHINE TOOL 8 Sheets-Sheet 2 Filed Nov. 4, 1936ama? M 0541 A TO \IZYS. 6 WM May 24, 1938.

F. A. PARSONS ET AL MACHINE TOOL 8 Sheets-Sheet 4 Filed Nov. 4, 1956 May24, 1938. F. A. PARsoNs ET AL MACHINE TOOL Filed Nov. 4, 1956 8Sheets-Sheet 5 I X I.

El i=5 May 24, 1938. F. A. PARSONS ET AL MACHINE TOOL Filed Nov. 4, 19368 Sheets-Sheet 6 Qwl RY n? 3% Q a Q? 0, E O Y Q? QM. my ANQ a LXVISXTORJfil Me y 1938- F. A. PARSONS El AL 2,113,353

MACHINE TOOL I Filed Nov. 4, 1936 s Sheets-Shet 'r q NVEN Tom 6 WRNEYS.

May 24, 1938.

F. A. PARSONS El AL MACHINE T001;

Filed Nov. 4, 1936 a sheets-sheefw 14. I jyVENTOM 73 B M M q anyways.

Patented May 24, 1938 UNITED STATES MACHINE 'roor.

Fred A. Parsons, Milwaukee, Wis., and Walter M. Pohl, Washington, D. 0.,assignors to Kearney & Trecker Corporation, West Allis, Wis., acorporation of Wisconsin Application November 4, 1936, Serial No.109,112

32 Claims.

This invention relates to machine tools and more particularly totransmission and control mechanism therefor, especially for millingmachines.

A purpose of the invention is to provide an improved transmissionmechanism particularly of the hydraulic type, and controls therefor,which may be used for either hand or automatic operation of a machinetool, and for machine 10 movements involving both hand and automaticcontrols, particularly for a, milling machine.

A particular object is to supplement the invention of a co-pendingapplication Serial No. 43,488 filed October 4, 1935, Patent 2,077,435,

15 April 20, 1937, with further inventions and improvements directedtoward the same general type of machine tool transmission and controlmechanism as is there shown and usable in combination therewith orsupplementary thereto.

., Further purposes relate to improved transmission and controlmechanism including improved means for the automatic reversal of machinemovements without use of lost motion mechanical snap-over devices, andincluding improved 25 automatic reverse means for effecting improvedaccuracy of reversal at a predetermined point of forward movement; andin which the direction improved manner with other transmission andcontrol mechanism of the machine, and especially for milling machines.

- A further purpose is toprovide an improved control mechanism at leastin part hydraulically operated for some or all of the control purposespreviously mentioned and especially where some of the control mechanismof the machine is manually operated, and particularly for a milling ma-45 chine.

A further purpose is to provide a transmission and control mechanismeffective for some or all of the improved results obtained by themechanism shown in other co-pending applications,

Serial No. 36,766, filed August 19, 1935, Patent 2,077,434, April 20,1937, and Serial No. 65,774 filed February 26, 1936, but in a formparticularly adapted for hydraulically actuated machine tools, andespecially for milling machines.

A further purpose is generally to simplify and improve the constructionand operation of machine tools, and particularly of milling machines,andstill other purposes will be apparent from the accompanyingdescription and. claims.

The invention consists in the construction and 5 combination of parts asherein illustrated, described and claimed and in such modifications ofthe structures illustrated and described as are equivalent to thestructure of the claims.

Like characters have been used to indicate the same parts throughoutthis specification, and in the drawings.

Fig. 1 is a right side elevation, partly in section, of a millingmachine incorporating the invention.

Fig. 2 is a front elevation of the same machine.

Fig. 3 is a sectional development of certain drive mechanism of themachine in enlarged scale. 1

Fig. 4 is an enlarged partial vertical section taken approximately alongline 4-4 of Fig. 1 and enlarged.

Fig. 5 is an enlarged partial elevation, partly in section, of the frontportion of the machine as viewed from the left of Fig. 2.

Fig. 6 is a portion viewed approximately from the line 6-6 of Fig. 5, inreduced scale, and partly in section.

Fig. 7 is a section through a pump of the machine, taken approximatelyalong line 'I'l of Fig. 6, and enlarged.

Fig. 8 is a semi-diagrammatic development of certain transmission andcontrol mechanism of the machine.

Fig. 9 is a partial front elevation of the machine, partially in sectionalong a line approxi mately corresponding to the line 9-9 of Fig. 1, andenlarged, the table portion being shown with a front cover removed.

Fig. 10 is an enlarged sectional view of a back pressure valve deviceused in the machine.

Fig. 11 is an enlarged sectional development taken approximately alongthe line ll-ll of Fig. 2.

Fig. 12 is an enlarged partial section taken approximately along theline |2-l2 of Fig. 2.

Fig. 13 is a partial section taken approximately along the line i3-I3 ofFig. 9.

Fig. 14 is a semi-diagrammatic development corresponding to themechanism shown at the lower right of Fig. 8 but enlarged.

The machine here shown is a milling machine which includes a base orsupport i, Fig. 1, a work table or support 2 slidably guided on base I,a tool spindle or support 3 rotatably carried by a quill or support 4slidably keyed and guided for transverse adjustment together withspindle 3 in a carrier or support 5. The carrier 5 is guided for bodilyvertical movement together with quill d and spindle 3 between sidemembers 6, i, Fig. 2, which are rigidly fixed on bed i and fixedtogether at the top by a member 8.

The guides for the various members may be of any suitable form andtherefore are not shown in detail. For the carrier 5 and quill 8 thereare providedsuitable manual means for the movement thereof and suitableclamp means operative in their several positions. Such moving andclamping means being old are not here shown.

Transmission mechanism for rotation of spindle 3 includes a primarymotion source such as an electric motor 9, Fig. 1, carried by base I,and having a drive shaft l8 carrying a pulley II, which drives a pulleyl2, Fig. 3, through belt means l3. Pulley I2 is fixed on a shaft Id anddrives a co-axial shaft |5 through a clutch generally denoted by thenumeral IS, the clutch including an outer member ll, an inner member IS,an adjustable abutment I9, a movable abutment 28, and a series offriction plates 2| alternately keyed to the outer and inner clutchmembers and slidable into mutual friction engagement by a pivoted lever22, which is operated by suitable cam surfaces 23a on a clutch spool 23shiftable by a fork member 28 fixed on a. shifter rod 25 which ismovable by means later described.

Shaft i5, at an intermediate point, carries a spindle reverser,generally denoted by the numeral 26, Fig. 8, comprising meshed bevelgears 21, 28, 29, the gears 27, 29 having clutch teeth alternativelyengageable by complementary clutch teeth on a clutch member 30 slidablykeyed on shaft I5, and which may be shifted by a manually operable lever3|, Fi 4, connected therewith.

by any suitable means, such as the eccentric and fork there shown. Thedriven gear 28 is fixed on a shaft 32, Fig. 4, which drives a shaft 33through a spindle rate changer, generally denoted by the numeral 34,comprising a plurality of differently diametered gear pairs such as thegears 35, '35 removably and interchangeably fixed on the differentshafts. Shaft 33 drives a vertical shaft 31 through bevel gears 38, 39.Shaft 31, Fig. 1, drives spindle 3 through bevel gears 90, 4|,extensible coupling 42, pinion 93 and a gear 98 which is fixed on thespindle.

The spindle train is provided with a brake, generally denoted by thereference letter a, Fig. 3, which includes an inner member I), keyed toshaft IS, an outer member c fixed with base a series of friction platesd, alternately keyed to the outer and inner members, an adjustableabutment e, a movable abutment f, and a pivoted lever g, which is movedto press the friction plates into mutual engagement by a member h fixedon the clutch spool 23.

The table -2 is alternatively driven through feed and quick traversetrains. The table feed train is driven from motor 9 through the mainclutch I6, Fig. 3, and-the shaft IS, the shaft l5 being extended todrive a sleeve 45, Figs. 5, 6, upon which is fixed a gear 96 meshingWith a pump drive gear 41, which drives a feed pump generally indicatedby the numeral 98, Fig. '7, housed within a unit 99, and fixed on bed I.Feed pump as here shown includes a plurality of pistons such as 50bodily rotatable with a member 5| which is driven from gear 41, andhaving more or less pumping stroke accordingly as a member 52 is shiftedto the right or left in Fig. 6, the member 52 being continuously pressedby springs, not shown, in the one direction and shifted in the otherdirection by the movement of a control plunger or rod 53 Figs. 5, 6, bymeans of mechanism later described.

Fluid is led to and away from the pistons 50 of feed pump 48 throughchannels 54, 55, Fig. 7 in a pintle 58 upon which member 5| is mountedfor rotation, the respective channels being connected to receive fluidfrom a supply channel 51 diagrammatically indicated in Fig. 8, and todeliver fluid to a channel 58 leading to table control mechanismgenerally denoted by the numeral 59, Fig. 8 which will be laterdescribed.

The quick traverse table train is driven from motor 9 to exclude clutchI6, Fig. 3, through a pair of gears 60, 6|, a shaft 62 which extendsforwardly to engage a sleeve 83, Fig. 6, similarly -to the engagement ofshaft l5 with the sleeve 45 10 which, like the feed pump channel 58, isconnected to the table control mechanism 59, Fig. 8 which will be laterdescribed.

Fluid from the pumps 48, 66, Fig. 8 may be delivered through the controlmechanism 59 to actuate a table motor, generally denoted by the numeralthrough the channels 12 or 13, according to the position of a reverserdevice including a reverser valve generally denoted by numeral 18, Figs.8, 9, and a feed or quick traverse rate selector including a rateselector.

valve '15, Fig-s. 8, 9, the motor 1| including a cyl inder I8, a piston11, and a piston rod 18 which is fixed with table 2.

The various control connections of the table control mechanism 59, Fig.8, areas follows:

Feed pump fluid from channel 58 passes to a port 19, Fig. 8, of reverservalve 14, which also includes ports 80, 8| respectively connected to thechannels l2, 13 leading to table motor II. In J the central position ofreverser valve 14, as shown in Fig. 8, the fluid from port 19 cannotreach either port 80, 8|, and the table motor 1| and table 2 are lockedinposition by the fluid on each side of piston 1! which then cannotescape past, valve M. In this central valve position the fluid from port19 is by-passed to an outlet channel 82 through ports 83, 84, to whichit passes,

through transverse holes 85, an axial bore and the transverse holes 81or 88.

But if the reverser valve 14, Fig. 8, is shifted to right or left of theposition in' Fig. 8, one or the other of the ports 89, 8| which connectto channels 12, 73 respectively will receive fluid from port 19 throughone of the annular grooves 89, 90, and the other port 80, 8| willdeliver fluid to one of the ports 83, 84 and outlet channel 82 throughthe other annular groove 89, 9|]. Thus the motor H and table 2 will bemoved in the one direction or the other according to the position ofvalve 14.

-Quick traverse pump fluid from channel I0, Fig. 8, passes to a port 9Iof valve I5. The valve I5 has two positions, namely, the feed rateposition shown in Fig. 8, in which the fluid from port 9I passes throughan annular groove 92 to a port 93 to be used for various purposes, aslater described, and another position, to-the left of that shown in Fig.8, in which the fluid from port 9I passes through groove 92 to aport-94, which communicates with the port I9 ofthe reverser valve 14. Inthe latter case the fluid delivered from channel I will be added to thatdelivered from channel 58 to produce relatively fast table movement ineither direction as controlled by reverser valve I4 as previouslydescribed.

The pumps 48, 66 are respectively provided with overload relief valves95, 96, Figs. 8, 9 which are of similar construction and therefore onlythe valve 96 will be described in detail. Valve 96 includes a plungermember 9! having an enlarged portion 98 acting as a piston andcontinuously urged by the fluid pressure of the pump appliedthrough aport 99, the plunger movement being opposed by pressure of a spring I00,which may be adjusted by a threaded member I 0| to vary the pressure.When the fluid pressure exceeds the maximum determined by the adjustmentof member ml the port 99-is opened to a channel I02 to permit fluid toreturn to reservoir 69.

The connections of the overload valves 95, 96 Fig. 8 to the pumps 48, 66and to the control valve 15 is such that when the table 2 is operatingat a feed rate the valve 95 controls the maximum table load capacity,while at quick traverse rate both the valves 95, 96 are connected toboth the pumps, and the load capacity is governed by whichever valve isadjusted for least pressure. Ordinarily this would be the valve 96.

It will be noted that, although both the feed pump and the quicktraverse pump are supplying fluid to table motor II during quicktraverse movements, the quick traverse rate will remain continuouslysupplied to the table motor unless the reverser valve I4 is in stopposition.

An automatic back pressure control device I03. Figs. 8, 10 is seriallyconnected withthe table 'motor outlet channel 82, the fluid passingthrough the device from a channel I04, which communicates with channel82, to an outlet I05 and thence to the reservoir 69. The device I03 issubstantially the same in construction and operation as run under allconditions of machine operation and particularly when the cutter tendsto set up a negative pressure or vacuum in the forward or motor supplychannel, and to automatically reduce the back pressure as the pressurein forward channel 94 increases and vice-versa, whereby'to avoid powerwaste, heating, and other undesirable results of a constantly high backpressure.

Feed pump 48, Fig. 8 is manually adjustable to change the feed ratebyme'chanism as follows:

A manually operable member II2, Figs. 2, 5, 11 is connected for movementof the pump control plunger 53, previously described, through a shaftII3, pinion II4, an intermediate gear II5, a gear II6, shaft III, acoupling H8, a shaft H9 and an the exposed end of the plunger 53. As themember II2 is turned in the one or the other direction plunger 53, whichis spring pressed together with member 52 as previously explained,follows the contour of cam member I20 thus altering the stroke of thefeed pump pistons. Associated with member II2 is an indicating deviceconsisting of a. graduated dial I 2I movable against an indicator I22which indicates on the dial the rate resulting from the variouspositions of the adjusting means. F

The reverser and selector valves I4, I5, are each movable from a leverI23, Figs. 2, 12. Lever I23 when oscillated to right or leftin Fig. 12shifts selector valve I5, Fig. 8, through a pivot I24 carried by asleeve. I25, an arm I 26 engaging a rod I2I, a pin I28, Figs. 9, 12, alever I29, a shaft I30, another lever I3I,- and a pin I32 engaging amember I33 fixed on a shifter rod I34, Figs. 8, 9 the shifter rod I34being co-axial with the valve I5, and coupled therewith by a pin I35.

Lever I23, when oscillated to right or left in Fig. 2 shifts reverservalve I4, Fig. 8, through sleeve I25, Fig. 12, a lever I36, a pin I31and a member I38 fixed on a shifter rod I39, Figs. 8, 12, which forconvenience is made in two parts I 39a, I391), joined together, andcoaxial with valve I4 to which the shifter rod is coupled by a pin I40.

For dog operation of the reverser valve I4, Fig. 8 there is provided atrip member I4 I, Fig. 9, having oppositely extended dog abutmentportions I4Ia, I4'Ib fixed on a sleeve I42, and alternatively rotatableinto the path of movement of table dogs such as I43, I44. A lever I45Figs. 9, 13, 14 fixed on sleeve I42 carries a pin I46 engaging a slot M1in the shifter rod I39 which is connected to reverser valve I4 aspreviously described.

When reverser valve I4 is in central or table stop position both theabutment members I4Ia, I4Ib are withdrawn out of the path of dogmovement but when the valve is shifted to establish movement of table 2the one or the other abutment is swung forward into the path of dogmovement, and will be contacted by a dog during table movement to returnthe valve to central position, thereby stopping the table.

For dog operation of feed and quick traverse eccentric cam member I20which operates against 1 When the sleeve I42 is in the positioncorresponding to the central or table stop position of reverser valve14, both abutments I49, I50 are withdrawn out of dog contactingposition, but during table movement one or the other of the abutments isswung forward and may then be contacted by dogs such as dogs II, I52respectively adapted for upward and downward post movement. A pin I53 isfixed in an arm I54 of a pivoted lever I55 and engages a suitable groovein the lower end of post I48, the lever I55 having another arm I56carrying a pin I51 which envice-versa, at desired points withoutinterference wih similarly operative dogs for the other direction oftable movement. Suitably spaced T, slots I59, I60, Fig. 9 are providedfor the upper and lower series of dogs. 1

Clutch I6 and brake a, Fig. 3, are shifted by the following mechanism.The shifter rod 25, Fig. 3 is provided with a piston I62 torwhich fluidmay be supplied from a suitable pressure source such as a pump I63, andcontrolled by valve means, such as I60. Pump I63 may be of any suitabletype, in this case comprising encased gears I65, I650; driven from shaft62, the pump having inlet and outlet ports suitably arranged, receivingfluid from a reservoir in base I, diagrammatically indicated at I61,Fig. 3, through a strainer I68 and a connecting channel I69, and

delivering fluid to valve means I60 through a channel I10.

The valve means I 60, Fig. 3 provides a port I1I supplied with fluidfrom channel I10, and the ports I12, I13 respectively connected bychannels I14, I15 with the opposite ends of piston I62. A valve plungerI16 is continuously urged in one direction by a spring I11 and may beurged in the other direction by fluid pressure derived through a channelI18 as later described. When member I16 is in its spring urgedposition,as. indicated in Fig. 3, the supply channel I communicates with port I13through a valve groove I19 and the piston I62 is then urged in adirection to disengage clutch I6 and to engage brake a, the fluid fromthe opposite end of piston I62 being forced out through channel I10,port I12, a valve groove I80 and a drain channel I8! which deliversfluid back to reservoir I61.

But when the channel I18. Fig. 3 is connected to a source of fluidpressure, as later described, the valve plunger I16 is shifteddownwardly in Fig. 3, and-fluid from channel I10 then reaches the otherside of piston I62 through the valve groove I80, port I12 and channelI14, waste fluid passing from the channel I through a drain channel I82to permit the, piston I62 to move in the direction to engage clutch I6.Pump I63 is also used for lubricating the machine as will be laterdescribed.

The control of fluid pressure inchanned I18, Fig. 3, for the shifting ofclutch I6 and brake a is primarily effected from a hand lever I83, Figs.

2, 12, which has two positions normally respectively effective to shiftpiston I62 and shifter rod 25, Fig. 3, to clutch engaged and to brakeengaged positions. The control effect of hand lever I83 may,'however bemodified by shifting another hand lever I84, Figs. 2, 1 2. In oneposition of the lever I84 the control effect of lever I83 is the normaleffect just described. In the other position of lever I84, the clutchengaged position of lever I83 is effective to engage the clutch I6 onlywhen selector valve 15, Fig. 8, is in feed position, and when the valveis in its quick traverse position the clutch I6 is disengaged and brakea. is engaged to stop spindle rotation. The means whereby these controleifects'are obtained-is as follows:

Pressure fluid for the channel I18, Fig. 3, which controls the clutch I6and brake a, as previously explained, is supplied through channels laterdescribed from a channel I85, Fig. 8, which also supplies other controlmechanism as later pointed out. The supply of fluid to channel I85 isderived from port 93 of selector valve 15, which in the feed position ofthe valve, as shown in Fig. 8, is supplied with fluid from quicktraverse pump 66 through port I and valve groove 92 In the quicktraverse position of valve 15, to the left of the position shown in Fig.8, the port 93 and iannel I85 receive fluid from the motor outletchannel 82, through a valve groove I86. In either case the fluidpressure in channel I85 is controlled by a relief valve generallydenoted by the numeral I81, Fig. 8, which communicates with channel I85and port 93 through channel I88, and is of a construction .similar tothat of relief valves 95, 96 previously described. The connection of therelief valve I81 to the valve port 93 also provides a constant pressureoutlet for the fluid from motor 1| during quick traverse movements,since the fluid is then under no necessity to pass through the backpressure device I03 previously described.

Fluid from channel I85 passes to a port I89 of a valve I90 Figs. 8, 14through a channel I9I, the valve I90 being operably connected to thehand lever I83, Figs. 2, 12, by the means of a shaft I92, a lever I93,and a pin I94 engaging a slot I95 in a member I96. In the position ofvalve I90 as shown in Figs. 8, 14, port I89 receives no fluid, but inthe other position of valve I90, 'to the right of the position shown inFigs. 8, 14,.the fluid passes through a valve groove I91 to a port I98,and thence to channels I99 and 200 respectively leading to a port 21 ofa valve 202 associated with the shifter rod I34, and to a port 203 of avalve 204, the latter valve being connected for operationfrom the handlever I80, Fig. 12, by the means of a shaft 205, and an eccentric pin206 engaging a slot 201 ina member 208, Figs. 8, 12, which is fixed onthe extended stem of valve 204.

The manner of delivery of fluid to the channel I18, Fig. 3, whichcontrols actuation of clutch shifter piston I62 and rod 25, aspreviously described, depends upon the position of valve 204, Fig. 14.In the position of the valve 204 there shown the fluid may pass from thechannel 200 through a valve groove 209, a port 2I0 and thence through achannel 2 to a port 212 of the valve 202. In such case, in eitherposition of the selector shifter rod I34, fluid will be delivered to aport 213 of valve 202 through a valve groove 2I4 from the one or theother of ports I or 2I2, provided that the valve I90 is in a position tothe right of thejposition of Fig. 14. In the left hand position of valveI90, as shown in Fig. 14, no fluid will be delivered to either port 20I,2I2 of valve 202, the fluid being unable to pass from port I89 to portI98 of valve I90.

The part 2I3, Fig. 14. of valve 202 is continube shifted to its positionengaging clutch I6 whenever valve I 90 is in its position to the rightin Fig.

14 and irrespective of the position of valve 202;

and the control valve I64 will be shifted by spring IT! to its positionengaging brake a whenever the valve I90 is shifted to the position shownin Fig. 14, the fluid pressure then being cut off at valve I90, and thepressure immediately leaking out of the various connecting channelsthrough a drain port 2I6, Fig. 14, which is exposed by the same lefthand movement of valve I98 that cuts off the pressure supply from portI89.

It will therefore be apparent from previous explanation that, in theposition of valve 204 as shown in Fig. 14, the clutch I6 will be engagedwhenever valve I 90 is shifted to the right by hand lever I83 and thebrake a will be engaged to stop the spindle 2 and feed pump 48 wheneverthe valve I90 and hand lever are shifted in the other direction.

But in the other position of valve 204, to the right of the positionshown in Fig. 14, no pressure fluid can reach the port 2 I2 of valve202, the port 2I0 then being closed from port 203, and in such casefluid can only pass to the channel I18 of control valve I64, Fig. 3,from port 201 of valve 202, and then only when shifter rod I34 is in itsfeed position as shown in Fig. 14. In the other or quick traverseposition of shifter rod I34 the port 20I is closed and the fluidpressure in the channels 2I5, and H8 immediately leaks out through port2I3, valve groove 2I4, port 2I2, channel 2I I, and port 2I0 which isthen exposed to drain through the bore 2 I I. When this occurs the valveI64 immediately shifts to its brake engaging position.

Thus, in the one position of valve 204 the control of clutch I6 andbrake a will be from hand lever I83, which engages the clutch I6 orbrake a independently of the feed or quick traverse position ofshifter-rod I34, while in the other position of valve 204 the shiftingof selector shifter rod I34 to feed position engages clutch I6, providedlever I83 is in clutch engaged position, and shifting rod I34 to quicktraverse position engages the brake. These control effects areindependent of which of the several means here shown are used forshifting the selector valve I5 and its shifter rod I34.

It is to be noted that, irrespective of the position of shifter rod I34and the selector valve I5, Fig. 8, the feed rate of table 2 cannot beeffected unless the spindle clutch I6 is engaged to rotate the spindle3. This is because the feed pump 48 is driven through the clutch I6 aspreviously explained, and therefore operates only when the clutch isengaged.

Thereverser valve I4, Fig. 8, in addition to the dog control previouslydescribed for shifting it to its central or motion interruptingposition, may also be dog controlled for effecting automatic reversalfrom either direction of movement of table 2 to the other direction. Themeans for effecting such dog controlled reversal is as follows:

A pivoted lever 2I8, Figs. 9, 13, 14 has a plurality'of arms 2I9, 220held normally central by spring plungers 22I, 222, which mayrespectively be depressed to turn the lever in the one or the otherdirection by the means of table dogs 223,

224 Fig. 9; Another lever am 225 carries a pin 226, Figs. 13, 14, whichengages a suitable slot 22'I in a sleeve 228 of a control valvegenerally denoted by the numeral 229, Fig. 14, the sleeve being axiallymovable in either direction from the normal central positionshown inFig. 14, by the operation of the dogs 222, 223. An inner member 230 ofvalve 229 is formed integral with the reverser shifter rod I391), and isaxially shiftable therewith.

In all positions of the valve sleeve 228, Fig. 14, fluid from the supplychannel I85 is delivered to a port 23I through channels 232, 233, a port234 and a valve groove 235. A piston 236 is fixed with shifter rod I39b, and may receive fluid pressure on the one piston face from a groove231 of valve 229 through a radial bore 238, an axial bore 239 andanother radial bore 240, or may receive fluid on the other piston facethrough a valve groove 24I and a passage 242. In the normal centralposition of valve sleeve 228 the supply port 23I is closed to both valvegrooves 231, 24I as shown in Fig. 14, but as shifter rod I39 and valvemember 230 are moved to right or left, the port 23I is brought intocommunication with the one or the other valve groove to deliver fluid tothat end of ,the piston which will urge movevment of the piston and ofshifter rod I39 in the same right or left direction, at the same timeopening the other valve groove and therefore the other end of the piston236 to a drain, the drain being provided in the one instance by a port243 which drains through a slot 244, and the drain being provided in theother instance by a chamber 245 and a drain passage 246.

In the operation just described, that is to say while sleeve 228 is inits normal or central position, the fluid pressure from valve 229 actsas detent means operating on piston 236 Fig. 14, to retain the rod I39and reverser valve I4, Fig. 8, in either of its table operatingpositions, and providing a central position of valve 229 in which thereverser valve I4 may be retained in central position for effecting atable stop, as previously explained. As long as sleeve 228 is permittedto remain in central position the operation of the dogs I43 and I44, tostop table movement as previously explained, would not be altered.

But if at the time of the operation of the dogs I43, I44, thecorresponding dog 223 or 224 is positioned to contact its plunger 22I or222, whereby to suitably shift sleeve 228 to right or left, in Fig. 14,as the case may be, then the valve member 230 will pass across theposition where port 23I is cut off from delivery of fluid to piston 236,and into a position where fluidpressure is urging the continued movementof piston 236 and shifter rod I39, before the dog I43 or I44 hascompleted its trip effect and before table movement stops. In such case,the fluid pressure from valve 229, acting on piston 236 will urgereverser valve I4 across central position and into the reverse position,thereby eifecting automatic reversal of the movement of table 2. At anearly point in the reverse movement the dog operating on the plunger 22Ior 222 backs away from the plunger and the plunger springs force sleeve228 again to normal central position, the fluid still continuing tooperate as a detent, as previously described, retaining reverser valveI4 and shifter rod I39 in whichever position it has been forced by theautomatic reversal 'just described.

It will also be obvious that, if the dogs 223, 224 and their connectionsto the sleeve 228are such as to sufficiently shift the sleeve, then itwill be unnecessary to use the dogs M3, I 44 to effect an initialmovement of the valve member 230, during reversal. In the presentinstance the dogs 43, M4 are unnecessary to effect automatic reversal,since the movement of the sleeve 228 from dogs 223, 224 is sufficient toreverse the-pressure operating on piston 236 in either table operatingposition of the reverser shifter rod I39.

The described mechanism is sufiicient for automatic table reversal butwithout addition the time required for reversal will vary with the rateof table travel. It is desirable at times, and particularly when table 2is operating at slow feed rates, to have the shifting of automaticreverser sleeve 228 proceed at a relatively very fast rate,substantially independently of the rate of movement of the table,whereby to reduce the time required for reversal. To effect thisresult', supplemental or additional means are used for shifting sleeve228, as follows:

A plunger 241, Figs. 8, 14 has enclosed ends whereby it may operate as apiston. At an intermediate point plunger 241 is provided with valvegrooves 248, 249 respectively connecting with the opposite plunger endsthrough axial bores 250, 25l and suitable radial bores such as 252, 253.When the plunger 241 is shifted slightly in either direction the one orthe other of grooves 248, 249 is brought into communication with a port254 which is continuously supplied with fluid from the channel I85through the channel 233, the annular groove which constitutes port 234of valve 229, and a channel 255; and the plunger 241 will then bequickly shifted by the fluid pres sure. Plunger 241 is connected formovement with the sleeve 228 by the means of a pm 256, Figs. 13, 14, inthe same lever arm 225 which actuates the sleeve, the pin engaging asuitable slot 251 in the plunger. The fluid admitted to plunger 241tends to quickly fully shift it in the same direction as started by dogs223, 224 operating on the plungers 22!, 222, and as a result of thearrangement described both the plunger 241 and sleeve 228 will bequickly fully shifted almost immediately following the start of theshifting of sleeve 228 in either direction from dogs 223 or 224 aspreviously described.

When either piston end of plunger241 is connected to shifter fluid fromthe port 254, the other piston endis connected to a drain, eitherthrough a direct drain hole 258 or through a drain hole 259 leading tothe chamber 245 and drain hole 246. After the completion of a reversemovement the fluid pressure is relieved on plunger 241, in a mannerlater described, to permit the return of the plunger and of sleeve 28and lever 2 ill to their normal central positions.

It is highly desirable in order to reduce operating time and for variousother reasons that at each automatic reversal of table 2 the reversemovement shall start at rapid traverse rate, but in many operationsthe'work and cutter are engaged up to the instant of reversal, and it isthen necessary'that the change to quick traverse rate must not beeffected prior to the actual reversal. Means are provided to insure eachof these desired results as follows:

When the reverser shifter rod I39, Fig. 14, has nearly completed itsshifting movement in either direction, the movement of piston 236 opensthe pressure end of the piston to a port 266, which therefore receivesshifter fluid in either completely shifted position of piston 236. vSuchfluid passes through a channel 26l to a valve groove 262 in theautomatic reverse plunger 41 and s there blocked when the plunger is 'inits normal, central position, as in Fig. 14. But when plunger 241 isshifted in either direction as during the and selector valve 15 to quicktraverse position,

but only during automatic reversal, and then only after the piston 236and the reverser valve 14 have substantially completed their reversingmovement. The other end of piston 261 is continuously connected to adrain channel 268 and when the automatic reverse plunger 241 is in'normal central position, that is to say at all times except duringautomatic reversal, the channel 266 is also connected to drain throughthe port 263 and a valve groove 269 which then communicates with thedrain channel 259, previously described. The arrangement of valve groove269 relative to port 263 and drain channel259 is such that in eitherposition of plunger 241 to effect automatic reversal the last mentioneddrain is out off, but at all other times the piston 261 is drained atboth ends as described and offers no resistance to movement of selectorshifter rod 834 in either direction.

After the piston 261, Fig. 14, has been shifted to effect quick traverseduring automatic reversal as just described, the operation of automaticreversal is complete, and it is then desirable that the fluid pressureon plunger 241 be relieved, in order that the plunger 241 and sleeve 228may return to normal central position as soon as the reverse tablemovement has moved the dog 223 or 224 away from its plunger 22I or 222.This is done by the following means.

An annular groove 210 is provided in the piston 261, Fig. 14, and afterthe piston moves to its quick traverse position, as described, duringreversal, groove 218 completes a channel connection between the twopiston ends of plunger 241, the connection then including a channel 21!,a channel 212 suitably connected therewith, the annular groove 216, andchannels 213, 214, 215. This connection equalizes the pressure on bothends of the plunger 241, which will then be moved to central normalposition by springs of plungers 221, 222, as soon as the plungers arefree from the dogs. Since the pressure is equalized on plunger 241whenever piston 261 and selector valve 15 are in quick traverseposition, the plunger 241 will not operate to effect rapid shifting ofsleeve 228, as above described, at such times as the reverse is to beeffected from a forward table movement at quick traverse rate, but thislimitation is of no importance since the fast table movement duringforward quick traverse effects comparatively very rapid movement ofsleeve 228 directly from the movement of the table dog and withoutnecessity for the supple- 8 Fixed on the table support or base I at therear of table 2 is a unit generally denoted by the numeral 21.6, Figs.5, 6, 8, having a main or body member 216a. Unit 216 includes ashiftable control valve member211, which is normally held in centralposition, as'in Fig. 8, by spring means as springs 218, 219, but whichmay be shifted axially in either direction when contacted by right orleft hand dogs such as 288, adjustably mounted on table 2.

Unit 216 also includes a piston plunger 28I, which is continuously urgedto the right in Fig. 8, by a spring 282, the pressure of which isadjustable by the means of an adjustable abutment member 283, threadedin the body 216a and locked in adjusted position by a nut 284.

When the valve 211 is in normal central position pressure fluid from thesupply channel I85, Fig. 8, is continuously delivered to the right handor piston end of plunger 28I through a suitable connecting channelindicated by dotted line 285, Fig. 8, a channel 286, channel 281, anannular port channel 288, channel 289, a port 298, a valve groove 29I, aport 292, and a channel 293. The result is to normally force the plunger28I to the left in Fig. 8, against the resistance of spring 282, untilthe plunger strikes a suitable abutment such as the inner end of theadjusting screw 283. At the sametime the chamber or cylinder 295 inwhich the plunger operates is maintained filled with liquid.

But if valve 211 Fig. 8, is moved slightly in either direction, by dogssuch as 288, the pressure fluid is cut off at the one or the other ofports 298, 292, and liquid under the pressure of spring 282 immediatelycommences to leak out of thechamber 295, there being suitable meansprovided preferably of constant area, and of material resi'stance, suchfor instance as a coil of tubing 296, having a' relatively small boreand connected to the chamber 295 by a channel 291 and tube 298. As theliquid leaks from chamber 295 the plunger 28Imoves to the right in Fig.8, the rate of movement being determined by the pressure exerted byspring 282 as determined by the adjustment of screw 283.

Almost immediately following the cutting off of fluid supply to chamber295 as described, an adjustable contact member 299 carried by the dog288 will abut the end of the body portion 216 and positively arrest themovement of table 2, which will then be maintained in this position bythe fluid pressure determined by the overload determined by theadjustment of member 283 to alter the spring pressure acting on theconstant area of the leakage channel 296. In the normal central positionof the valve 211 the port 382 is through a valve groove 3.83, a channel384, a pipe 385 suitably connected with another pipe 386,

and the channel 215. And when table movement to the right in Fig. 8 hasshifted valve 211 to the right, channel 38I delivers fluid to the leftend of plunger 241 through a valve groove 381, a channel 388, a pipe 389suitably connected with another pipe 3l8 and the channel 2". The concam3 I I, Fig. 5, is fixed on a sleeve 3I2 for actuation of the pumpadjusting plunger 53 in a manner similar to the cam I28previously-described, and is connected for movement from a cam 3I3adjustably fixed on table 2, Figs. 5, 6, through a cam follower 3I4adjustably fixed on a shaft 3I5, a segment lever 3I6, also'flxe d onshaft 3I5; an idler gear 3", and a gear 3l8 fixed on the sleeve 3I2. Thecam follower 3I4 is continuously urged against the cam 3l3 by a spring3I9 and the pump adjusting cam 3 thus forced to adjust the pump duringtable movement in accordance with the configuration of cam 3I3. Therange or ratio of feed rates thus obtained, and the table feed rate atany given position of table movement is, therefore, determined by theform and position of the cam 3| 3, but the series of rates determined bythe cam may be raised or lowered by the adjustment of cam follower 3I4relative to shaft 3I5, an adjusting screw 328 being provided for thispurpose.

The pump I63, Fig. 3, which supplies fluid for operating clutch I6 andbrake a, as previously described, is also used for lubricating themachine as is more fully disclosed in a co-pending application SerialNo. 86,559, filed June 22, 1936. The cylinder of piston I62 is providedwith a port 32I which is opened to the pressure fluid actuating thepiston but only after the piston has completed its movement in eitherdirection, this fluid is directed to any points requiring lubricationthrough a channel 322 and a lubricant supply pipe 323. For thelubricating supply there is provided a pressure control valve 324,comprising a spring pressed ball 325, the excess fluid passing through adrain hole 326 to return to reservoir I61, as does also any excess ordrain from the various parts lubricated from pipe 323. The system shownprovides a high pressure fluid supply for the shifting of the clutch I5and brake a, but limits the duration of high pressure to the very briefinterval while the piston I62 is being shifted, thereby avoiding powerwaste and heating of the fluid.

What is claimed is:

1. In a machine tool the combination'of a transmission mechanismincluding a member shiftable to alternative positions for altering thetransmission effect, a piston connected for shifting said member, acylinder for said piston, said piston having alternative positionscorresponding to the member positions, a pressure fluid source, channelmeans for connecting said source with the opposite cylinder. ends,control valve means having alternative positions respectivelycorresponding with the different piston positions and associated withsaid channel means fordirecting '7 the pressure fluid to the one or theother cylin- &

2. In a machine tool the combination of a transmission including amember shiftable to alternative positions for altering the transmissionefiect, a piston connected for shifting said memher and havingalternative positions corresponding to the member position, a cylinderfor said piston, a positive acting fluid pump, supply channel meansconnectible between said pump and cylinder, said cylinder providing anoutlet chan nel, valve means associated with said supply channel meansto control the connections of said pump and cylinder and havingalternative positions corresponding to the piston positions, thecylinder connection of said supply channel and outlet channel beingspaced to prevent communication therebetween until said piston has movedto the position corresponding to the position of said valve means.

3. In a machine tool the combination of a rotatable spindle, areciprocable support, a spindle transmission including means shiftablefor alternatively establishing or interrupting spindle rotation, asupport transmission including a pressure fluid source, a fluid operablemotor connected for support movement and channel means connectiblebetween said source and motor, valve means associated with said channelmeans and adjustable for efiecting reversal of support movement and foralternatively efiecting a feed rate or a relatively fast quick traverserate, a plurality of independently operable controllers respectively forshifting said shiftable means, for adjusting said valve means to reversethe direction of support movement, and for adjusting said valve means tochange from the one to the other of said rates, shifting said valvemeans to effect reversal of said support substantially simultaneouslywith a change of rate thereof and shifting said shiftable means toeffect interruption of spindle rotation, and additional control meansincluding elements relatively adjustable to selectively include orexclude the shifting of said shiftable means in the operation of saidother control means.

4. In a machine .tool the combination of a tool support and a worksupport, a transmission including a feed rate pump, a quick traverserate pump and a reversible motor connected for relative movement of saidsupports, reverser valve means having alternative forward and reversepositions, channel means connecting said reverser valve means and motor,a passageway connectible between said quick traverse rate pump andreverser valve means, shiftable valve means having alternative positionsrespectively opening and closing said passageway, and another passagewayconnecting said quick traverse rate pump and reverser valve meansthrough said feed rate pump exclusive of said shiftable valve means.

5. In a machine tool the combination of a tool support and a worksupport, a transmission including a feed rate pump, a quick traverserate pump and a reversible motor connected for relative movement of saidsupports, reverser valve means having alternative forward and reversepositions, channel means connecting said reverser valve means and motor,a passageway connectible between said quick traverse rate pump and.reverser. valve means, shiftable valve means having alternativepositions respectively opening and closing said passageway, anotherpassageway connecting said quick traverse rate pump and reverser valvethrough said feed rate pump exclusive of said shiftable valve means, anda plurality of relief valves respectively connected with the firstmentioned passageway at a point between said quick traverse rate pumpand shiftable valve means, and connected to said other passageway at-apoint between said feed rate pump and reverser valve means.

'6. In a machine tool the combination of a tool support and a worksupport, a transmission including a feedrate pump, a quick traverse ratepump and a reversible motor connected for relative movement of saidsupports, reverser valve means having alternative forward and reverse.positions, channel means connecting said reverser valve means and motor,a passageway connectible between said quick traverse rate pump andreverser valve means, shiftable valve means having alternative positionsrespectively opening and closing said passageway, another passagewayconnecting said quick traverse rate pump and reverser valve meansthrough said feed rate pump exclusive of said shiftable valve means, andcontrol means for said transmission including a plurality of controllersrespectively connected for independent shifting of said reverser valvemeans and of said shiftable valve means, and another 7. In a machinetool the combination of a tool support and a work support, atransmission including a feed rate pump, a quick traverse rate pump anda reversible motor connected for relative movement of said supports,reverser valve means having alternative forward and reverse positions,channel means connecting said reverser valve means and motor, apassageway connectible between said quick traverse rate pump andreverser valve means, shiftable valve means having' alternativepositions respectively opening and closing said passageway, anotherpassageway connecting said quick traverse rate pump and reverser valvemeans through said feed rate pump exclusive of said shiftable valvemeans, a plurality of manually operable controllers respectively forshifting said reverser valve means independently of said shiftable valvemeans and for shifting said shiftable valve means independently of saidreverser valve means, and another controller invariably operable forsubstantially simultaneously shifting said reverser valve and shiftingsaid shiftable valve means to the position opening the first mentionedpassageway.

8. In a machine tool the combination of a tool support and a worksupport, a transmission including a feed rate pump, a quick traverserate pump and a reversible motor connected for relative movement of saidsupports, reverser valve means having alternative forward and reversepositions, channel means connecting said reverser valve means and motor,a passageway connectible between said quick traverse rate pump andreverser valve means, shiftable valve means having alternative positionsrespectively opening and closing said passageway, another passagewayconnecting said quick traverse rate pump and reverser valve meansthrough said feed rate pump exclusive of said shiftable valve means, aplurality of manually operable controllers respectively for shiftingsaid reverser valve means independently of said shiftable valve meansand for shifting said shiftable valve means independently of saidreverser valve means, a power source having normally inoperativeconnections for substantially simultaneously shifting said reverservalve means and shifting said shiftable valve valve means, shitablevalve means having alternative positions respectively opening andclosing said passageway, another passageway connecting said quicktraverse rate pump and reverser valve means through said feed rate pumpexclusive of said shiftable valve means, a plurality of menuallyoperable controllers respectively for shifting said reverser valve meansindependently of said shiftable valve means and for shifting saidshiftable valve means independently of said reverser valve means, fluidoperable shifters respectively connected with said reverser valve meansand with said shiftable valve means, a fluid pressure source, andanother controller shiftable for connecting said source and shifters forsubstantially simultaneously shifting said reverser valve means andshifting said shiftable valve means to the position opening the firstmentioned passageway.

10. In a machine tool the combination of a tool support and a worksupport, a transmission including a feed rate pump, a quick traverserate pump and a reversible motor connected for relative movement ofsaidsupports, reverser valve means having alternative forward andreverse positions, channel means connecting said reverser valve meansand motor, other channel means connectible between eachof said pumps andsaid reverser valve means, shiftable valve means controlling theconnection of said other channel means to effect an alternative feed orquick traverse rate connection while continuously maintaining a drivingconnection from at least one of said pumps, a first controller forshifting said reverser valve means independently of said shiftable valvemeans, a second controller for shifting said shiftable valve meansindependently of said reverser valve means, and a third controller forsubstantially simultaneously shifting said reverser valve means andshifting said shiftable valve means to effect said quick traverse rateconnection.

11. In a machine tool the combination of a tool support and a worksupport, a transmission including a feed rate pump, a quick traverserate pump and a reversible motor connected for relative movement of saidsupports, reverser valve means having alternative forward and reversepositions, channel means connecting said reverser valve and motor, otherchannel means connectible between each of said pumps and said-reverservalve means, shiftable valve means controlling the connection of saidother channel means to effect an alternative feed or quick traverse rateconnection while continuously shiftable valve means, a second controller,for shifting said shiftable valve means independently of said reverservalve means, a third controller for substantially simultaneouslyshifting said reverser valve means and shifting said shiftable valvemeansto eifect said quick traverse rate connection, and dog operablemeans operable in accordance with said relative support movement foroperation of said second controller and subsequent operation of saidthird controller.

12. In a. machine tool the combination of a tool support and a worksupport, a transmission including a feed rate pump, a quick traverserate pump and a reversible motor connected for relative movement of saidsupports, a fluid reservoir for supply of fluid to said pumps, channel.

means connectible between said pumps and motor, reverser valve meansassociated with said channel means and operable for controlling thedirection of said motor, shiftable valve means associated with saidchannel means and operable for controlling alternative motor actuationat feed or quick traverse rate, a plurality of back pressure controlvalves, means controlling the back pressure capacity of one of said backpressure valves in accordance with variations in the forward pressure onsaid motor, a pluralityof outlet channels each connectible between saidreverser valve means and reservoir and respectively through different ofsaid back pressure control valves, and valve means alternatively openingor closing one of said outlet channels inaccordance with the shifting ofsaid shiftable valve means.

' 13. In a machine tool the combination of a tool support and a worksupport, a transmission including a feed rate pump, a quick traverserate pump and a reversible motor connected for relative movement of saidsupports, a fluid reservoir for supply of fluid to said pumps, channelmeans connectible between said pumps and motor, re-

verser valve means'associated with said channel means and operable forcontrolling the direction ofsaid motor, shiftable valve means associatedwith said channel means and operable for controlling alternative motoractuation at feed or quick traverse rate, a plurality of back pressurecontrol valves, means controlling the back pressure capacity of one ofsaid back pressure valves in accordance with variations in the forwardpressure on said motor, a plurality of outlet channels each connectiblebetween said reverser valve means and reservoir and respectively throughdifferent of said back pressure control valves, and valve meansalternatively opening or closing the outlet channel connected throughthe other of said back pressure control valves in accordance with theshifting of said, shiftable valve means.

l4. In a machine tool the combination of a tool support and a worksupport, a transmission including a feed rate pump, a quick traverserate pumpand a reversible motor connected for relative movement of saidsupports, a fluid reservoir for supply of fluid to said pumps, channelmeans connectible between said pumps and motor, reverser valve meansassociated with said channel means and operable for controlling thedirection of said motor, shiftable valve means associated with saidchannel means and operable for controlling alternative motor actuationat feed or quick traverse rate, a plurality of back pressure controlvalves, means controlling the back pressure capacity of one of said backpressure valves in accordance with variations in the forward pressure onsaid motor, manually adjustable means controlling the back pressurecapacity of the other of said back pressure control valves. outletchannels respectively connecting said reverser valve means and reservoirthrough different of said back pressure control valves, and valve meansalternatively opening or closing one of said outlet channels inaccordancewith the shifting of said shiftable valve means.

15. In a machine tool the combination of a tool support and a worksupport, a transmission for relative movement of said supports includinga pressure fluid supply source, a reversible fluid operable motor, andchannel means connectible between said source and motor, reverser valvemeans associated with said channel means and operable for changing thedirection of motor a0- tuation, a power operable shifter connected withsaid reverser valve means, a positive stop device comprising a plungerand an abutment adapted to contact and shift said plunger during saidrelative movement, said device preventing said relative movement fartherin the same direction following a predetermined shifting of saidplunger, a power source connectible with said shifter, and meanscontrolling the connection of said power source and shifter inaccordance with the position of said plunger.

16. In a machine tool the combination of a tool support and a' worksupport, a transmission for relative movement of said supports includinga pressure fluid supply source, a reversible fluid operable motor, andcharmel means connectible between said source and motor, reverser va'vemeans associated with said channel means and operable for changing thedirection of motor actuation, a power operable shifter connected withsaid reverser valve means, a positive stop device comprising a plungerand an abutment adapted to contact and shift said plunger during saidrelative movement, said device preventing said relative movement fartherin the same direction following a predetermined shifting of saidplunger, a power source connectible with said shifter, means initiallyoperated in accordance with the shifting of said plunger forsubsequently connecting said power source and shifter, and meansadjustably controlling the interval between said shifting of saidplunger and said connection of the mwer source.

17. In a machine tool the combination of a tool support and a worksupport, a transmission for relative movement of said supports includinga pressure fluid supply source, a reversible fluid operable motor, andchannel means connectible between said source and motor, reverser valvemeans associated: with said channel means andoperable for changing thedirection of motor actuation, a fluid operable shifter for said reverservalve means, a positive stop device including a plunger and an abutmentadapted to contact and shift said plunger during said relative movement,said device preventing said relative movement farther in the samedirection following a predetermined shifting of said plunger, a pressurefluid source connectible with said shifter,

shiftable valve means controlling the connection of the pressure fluidsource last mentioned, and means operative to shift said shiftable valvemeans following said predetermined shifting of said plunger.

18. In a machine tool the combination of a tool support and a worksupport, a transmission for relative movement of said supports includinga pressure fluid supply source, a reversible fluid op rable motor, andchannel means connectible arrests between said source and motor,reverser valve means associated with said channel means and operable forchanging the direction of motor actuation, a fluid operable shifter forsaid reverser valve means, a positive stop device including a plungerand an abutment adapted to contact and shift said plunger during saidrelative movement, said device preventing said relative movement fartherin the same direction following a predetermined shifting of saidplunger, a pressure fluid source connectible with said shifter,shiftable valve means controlling the connection of the pressure fluidsource last mentioned, means initially operated in accordance with theshiftin of said plunger for subsequently shifting said shiftable valvemeans, and means adjustably controlling the interval between saidshifting of said plunger and said shifting of said shiftable valvemeans.

19. In a machine tool the combination of a tool support and a worksupport, a transmission for relative movement of said supports includinga pressure fluid supply source, a reversible fluid operable motor, andchannel means connectible between said source and motor, reverser valvemeans associated with said channel means and operable for changing thedirection of motor actuation, a fluid operable shifter for said reverservalve means, a positive stop device including a plunger and an abutmentadapted to contact and shift said plunger during said relative movement,said device preventing said relative movement farther in the samedirection following movement of said plunger to a predeterminedposition, a pressure fluid source connectible with said shifter,shiftable valve means controlling the connection of the pressure fluidsource last mentioned, a

fluid pressure chamber normally supplied with pressure fluid, a fluidleakage channel communi-P cating with said chamber, a fluid operablepiston, a channel connecting said piston and chamber for movement oisaid piston in one direction, adjustable pressure means for movement ofsaid 7 piston in the other direction, means for shifting shifter, apositive stop device comprising a plunger and an abutment adapted tocontact and shift said plunger to a predetermined position during saidrelative movement, a fluid pressure chamber, a fluid leakage channelcommunicating with said chamber, a fluid operable piston, a channelcon-= necting said piston and chamber for movement of said piston in onedirection, adjustable pressure means urging said piston in the otherdirection, a power source, a pressure fluid source normally connectedfor supply of fluid to said chamber, means operable upon movement ofsaid piston in said other direction for connecting said power source andreverser piston, and means operative upon movement of said plunger tosaid predetermined position to disconnect said fluid supply source andchamber.

21. In a machine tool the combination of a pluport movement, a dogoperable controller for connection of said supplemental power means, anda dog movable in accordance with said relative movement for operation ofsaid controller.

22. In a machine tool the combination of a plurality of relativelymovable supports, a transmission for said relative movement including areversibly fluid operable motor, a fluid pressure source and channelmeans connectible from said source for operation of said motor in eitherdirection, reverser valve means associated with said channel means, afluid operable shifter for said reverser valve means, pump meansconnectible with said shifter, a control valve shiftable to connect saidpump means and shifter to effect reversal of said relative movement,supplemental power means for shifting said control valve independentlyof support movement, a dog operable controller for said supplementalpower means, and a dog movable in accordance with said relative movementfor operation of said controller.

23. In a machine tool the combination of a plurality of relativelymovable supports, a transmission for said relative movement including areversibly fluid operable motor, a fluid pressure source and channelmeans connectible from said source for operation of said motor in eitherdirection, reverser valve means associated with said channel means, afluid operable shifter for said reverser valve means, pump meansconnectible with said shifter, a control valve shiftable to connect saidpump means and shifter to effect reversal of said relative movement, asupplemental fluid operable shifter for shifting said control valve, afluid supply source for said supplemental shifter, a dog operablecontroller for connection of said supply source and supplementalshifter, and a dog movable in accordance with said relative movement foroperation of said controller.

24. In a machine tool the combination of a plurality of relativelymovable supports, transmission mechanism for relative movement of saidsupports including a reversibly fluid operable motor, a pressure fluidsupply source and channel means connectible between said source andmotor for movement thereof alternatively in opposite directions andalternatively at feed or quick traverse rate, valve means associatedwith said channel means and shiftable to effect either motor directionand to effect a change from one to the other of said rates, a firstcontroller for said valve means and operable for effecting a change inmotor direction independently of a change in rate thereof, a secondcontroller for said valve means and operable for effecting a. change inmotor rate independently of a change in direction thereof, a thirdcontroller for said valve means and operative for substantiallysimultaneously effecting a change both of motor direction and motorrate, a power source, shifter means for said third con-' necting saidsupplemental power means and member, and a dog movable in accordancewith said relative movement for operation of saidcontrol device.

25. In a machine tool the combination of a plurality of relativelymovable supports, transmission mechanism for relative movement of saidsupports including a reversibly fluid operable motor, a pressure fluidsupply source and channel means connectible between said source andmotor for'mov'ement thereof alternatively in opposite directions andalternatively at feed or quick traverse rate, valve means associatedwith said channel means and shiftable to effect either motor directionand to effect a change from one to another of said rates, a firstcontroller for said valve means and operable for effecting a change inmotor direction independently of a change in rate thereof, a secondcontroller for said valve means and operable for effecting a change inmotor rate independently of a change in direction thereof, a thirdcontroller for said valve means and operative for substantiallysimultaneously effecting a change both of motor direction and motorrate, a fluid operable shifter for said third controller, pump meansconnectible for operation of said shifter, control valve meanscontrolling the connection of said pump means and shifter, supplementalpower means for shifting said control valve means, a dog operablecontroller for said supplemental power means, and a dog movable inaccordance with said relative movement for operation of said dogoperable controller.

26. In a machine tool the combination of a plurality of relativelymovable supports, transmission mechanism for relative movement of saidsupports including a reversible fluid operable motor, a pressure fluidsupply source and'channel means connectible between said source andmotor for movement thereof alternatively in opposite directions andalternatively at feed or quick traverse rate, valve means associatedwith said channel means and shiftable to efiect either motor directionand to effect a change from one to another of said rates, a firstcontroller for said valve means and operable for effecting a change inmotor direction independently of a change in a supplemental fluidoperable shifter for shifting said control valve means, a fluid supplysource for said supplemental shifter, a dog operable controller forconnection of said supplemental source and supplemental shifter, and adog movable in accordance with said relative movement for operation ofsaid dog operable controller.

27. In a machine tool the combination of a plurality of relativelymovable supports, a transmis- 'sion for said relative movement-includinga reversibly fluid operable motor, a fluid pressure source and channelmeans connectible from said source for operation of said motor in eitherdirection, reverser valve means associated with said channel means, apower source, a power operable shifter for said reverser valve means, amember shiftable for eflecting' the connection of said u supportmovement, a dog operable controller for connection of said supplementalpower means, a dog movable in accordance with said relative movement foroperation of said controller in one direction, and automatic means fordisconnecting said supplemental power means subsequent to the shiftingof said member.

28. In a machinetool the combination of a plurality of relativelymovable supports, transmission mechanism for relative movement of saidsupports including a reversibly fluid operable motor, a pressure fluidsupply source and channel means connectible between said source andmotor for movement thereof alternatively in opposite directions andalternatively at feed or quick traverse rate, valve meansassociated withsaid channel means and shiftable to effect either motor direction and toeffect a change from one to-another of said rates, a first controllerfor said valve means and operable for effecting a change in motordirection independently of a change in rate thereof, a second controllerfor said valve f'zmeans and operable for efiecting a change in motorrate independently of a change in direction thereof, a third controllerfor said valve means and operative for substantially simultaneouslyeffecting a change both of motor direction and motor rate, a powersource, shifter means for said third controller, a member shiftable foreffecting a connection, of said power source and shifter means,supplemental power means for shifting said member, a dog operablecontrol device for connecting said supplemen- -tal power means andmember, a dog movable in accordance with said relative movement foroperation of said control device for connecting said supplemental powermeans and member, and automatic means for disconnecting saidsupplemental power means at a predetermined interval subsequent totheshifting of said member.

29. In a machine tool the combination of a plurality of relativelymovable supports, a transmission for said relative movement including areversibly fluid operable motor, a fluid pressure source and channelmeans connectible from said source for operation of said motor in eitherdirection, reverser valve .means associated with said channel means, amanually operable controller for shifting said reverser valve means toopposite direction positions, a fluid operable shifter for said reverservalve means, a pressure 'fiuid source for said shifter, control valvemeans for altering the connection of said source and shifter andincluding a valve member movable in accordance with the movement of saidshifter and a complementary valve member having a position normallycooperative with the first menaiiaaea tioned valve member to connectsaid pressure source and shifter to yieldably retain said reverser valvemeans in the direction position effected by said manual controller, asupplemental power operable shifter for said complementary valve member,a supplemental power source for said supplemental shifter, a dogoperable controller for connecting said supplemental source andsupplemental shifter to effect movement of said complementary valvemember to a position connecting said fluid operable shifter to 'shiftsaid reverser valve means to the other direction position, and a dogmovable in accordance with said relative movement for operation of saiddog operable controller.

30. In a machine tool the combination of a plurality of relativelymovable supports, trans-- mission mechanism for movement of saidrelatively movable supports including means shiftable for alternativeopposite direction of move- -ment and for efiecting alternative feed orquick traverse rate, a first controller for effecting a change indirection independently of a change of rate, a second controller foreffecting a change of rate independently of a change of direction, aplurality of fluid operable piston devices respectively connected foroperation of said first and second controllers, a pressure fluid supplysource, and control means operable to connect said source to operatesaid first controller piston device and subsequently invariably tooperate said second controller piston device, whereby to effect a'changeof rate substantially simultaneously with reversal.

31. In. a machine tool having a plurality of relatively movable supportsand hydraulic transmission mechanism for effecting said relativemovement in either of opposite directions and at either of feed or quicktraverse rates, the combination of valve means shiftable for alteringthe rate and direction of said movement, first and second controllersrespectively for shifting said valve means for independent change ofdirection and of rate, power operable control means for shifting saidvalve means for substantially simultaneously effecting a change ofdirection and a change of rate and including a shiftable member, a dogmovable in accordance with the rate of said relative movement, and powermeans for shifting said member at a relatively very'rapid rate andincluding an element contacted by said d s. I

32. A machine tool as specified in claim 31 in which said power operablecontrol means includes means limiting the operation thereof to effect aquick traverse rate immediately following reversal.

FRED A. PARSONS. WALTER. M. POI-IL.

